From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bob Peterson Date: Tue, 5 May 2015 12:43:29 -0400 (EDT) Subject: [Cluster-devel] [GFS2] gfs2: handle NULL rgd in set_rgrp_preferences In-Reply-To: <1430837473-51806-1-git-send-email-adas@redhat.com> References: <1430837473-51806-1-git-send-email-adas@redhat.com> Message-ID: <1778877507.12265434.1430844209063.JavaMail.zimbra@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit ----- Original Message ----- > The function set_rgrp_preferences() does not handle the (rarely > returned) NULL value from gfs2_rgrpd_get_next() and this patch > fixes that. > > The fs image in question is only 150MB in size which allows for > only 1 rgrp to be created. The in-memory rb tree has only 1 node > and when gfs2_rgrpd_get_next() is called on this sole rgrp, it > returns NULL. (Default behavior is to wrap around the rb tree and > return the first node to give the illusion of a circular linked > list. In the case of only 1 rgrp, we can't have > gfs2_rgrpd_get_next() return the same rgrp (first, last, next all > point to the same rgrp)... that would cause unintended consequences > and infinite loops.) > > Resolves: rhbz#1211663 > Signed-off-by: Abhi Das > --- > fs/gfs2/rgrp.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c > index cb27065..900e515 100644 > --- a/fs/gfs2/rgrp.c > +++ b/fs/gfs2/rgrp.c > @@ -978,10 +978,10 @@ static void set_rgrp_preferences(struct gfs2_sbd *sdp) > rgd->rd_flags |= GFS2_RDF_PREFERRED; > for (i = 0; i < sdp->sd_journals; i++) { > rgd = gfs2_rgrpd_get_next(rgd); > - if (rgd == first) > + if (!rgd || rgd == first) > break; > } > - } while (rgd != first); > + } while (rgd && rgd != first); > } > > /** > -- > 1.8.1.4 > > Hi, Thanks. Now in the for-next branch of the linux-gfs2 git tree. FYI: I removed "Resolves:" for upstream. Regards, Bob Peterson Red Hat File Systems